This invention relates to anti-skid chains such as those used on automobiles, trucks and the like.
Tire chains most commonly used include an inner side chain, an outer side chain, and cross chains connected therebetween, one end of each side chain being provided with a hook suitable for connecting both ends of each side chain. When the chains are in position around the tire, the cross chains extend over the tread of the tire and provide a gripping surface which increases the traction of the tire in mud, snow, or ice.
Side chains are commonly welded straight link chains and cross chain end hooks are folded over one bar of the side chain link. This requires a highly technical welding process and quality control, and cross chain end hooks are subjected to abrasive wear because of the alternating drive forces against the end hooks, thus causing distortion of the end hooks under strain. Accordingly, a need exists for a high strength weldless or minimally welded linkage to connect the side chain and cross chain.
In U.S. Pat. No. 1,617,627 to Frambach a side chain link integrating the cross chain attachment is disclosed in which two terminal ends of the bar forming the link, placed adjacently at one end, comprise the attachment to the adjoining side chain link. Because the attachment is subjected to inter-link motion and abrasion, the side chain end hooks of this invention become weakened thus allowing the end hooks to unwrap before optimum chain life is achieved. By the time service of the cross chain is normally needed, manipulation of the side chain end hook may accelerate failure, because the end hook tends to bend severely at the wear point as it is being opened. Frambach's link and U.S. Pat. No. 1,758,739 to Evans are alike difficult to serve the cross chains when needing replacement.
Also in Evans, the right angular force exerted by the cross member against the longitudinal side chain line adds forces to the terminal end wrap which would tend to unwrap at least one terminal end wrap no matter where the cross member loop is placed on the link.
The present invention further relates to tire chains which make the connection of the inner side member by using an extension on one end of the inner side member which completes the inner side member connection from a point remote from the actual point of connection, then further extends to the outer side member thereby forming an additional cross member. One embodiment of this type of inner connection is described in my patent application Ser. No. 662,432 filed Mar. 1, 1976.
U.S. Pat. No. 2,553,849 to Dines and Swiss Pat. No. 435,002 to Fullemann also show extension side chains which ultimately form an additional cross chain by various connection arrangements. Dines and Fullemann do not employ automatically engaged inner connection and the extension itself is easily attached in an undesireable twisted condition, hence a need exists for an improved connection means on the extension occupying only a narrow space width, and utilizing commonly used cross chain components.